1. Field of the Invention
The invention relates to non-laminated, impression surface conveyor belting and to methods of its manufacture.
2. Brief Description of the Prior Art
A review of the prior art is contained in Man Made Textile Encyclopedia, pages 309-312. In general, textile based conveyor belting is made by the so-called "wet-woven PVC" method wherein polyester warp yarns are immersed in polyvinyl chloride compound and then woven together while wet. Alternatively, belting may be made by lamination of textile cloths with elastomeric sheets. The resultant belting is not entirely satisfactory for all purposes. For example, the laminated belts are subject to delamination and structural failure over periods of use. Further, the prior art method of producing an impression surface belting comprised sewing or weaving a fibrous bundle or fabric "button" or like protuberance onto the surface of the belting fabric and surface coating the resultant fabric with an elastomer. The "button," a fibrous bundle, was particularly subject to abrasive action and readily abraded away from the base belting or flattened. A great deal of hand labor was also required, making the prior art method laborious and costly.
The method and belting of our invention represent improvements in the art. The method of manufacture is economical, efficient and produces an advantageous non-laminated product. The belting of the invention is useful in the manufacture of impression surfaced conveyor belts which exhibit advantageous properties of resistance to abrasion (particularly on the edges) and fraying, flexibility, and structural and running stability. The non-laminated belting of the invention obviates the prior art problem of delamination. Impression surface belting is useful in conveyor applications for the sorting and separation of articles, particularly sheet materials such as tobacco leaves and the like.